1. Field of the Invention
The present invention relates to an optical flip-flop circuit operated on the basis of a new operation principle.
2. Description of Related Art
The flip-flop circuit is an electronic circuit having two stable states of “ON” and “OFF” or “HIGH” and “LOW”. That is, the flip-flop circuit is a basic electronic circuit element in which when these two stable states are made to correspond to “0” and “1”, information of 1 bit can be held, and in addition to that, the two states can be alternately changed.
According to rapid progress of the optical communication technique and the optical information processing technique that has been recently made, in the field of optical technique, investigations and developments of an optical flip-flop circuit corresponding to a conventional flip-flop circuit, which is a basic electronic circuit, have been made. Therefore, some proposals relating to the optical flip-flop circuit have been made.
For example, JP-A-6-95194 discloses the following technique. An oversaturation absorbing region of a bistable laser, the substrate polarity of which is “n”, and an oversaturation absorbing region of a bistable laser, the substrate polarity of which is “p”, are connected to each other through a bias. When one of the bistable lasers makes oscillation, the other of the bistable lasers stops oscillation. In this way, the optical flip-flop circuit operates as an optical inverter circuit.
JP-A-4-130316 discloses the following technique. All elements are monolithically accumulated on the same substrate by using a semiconductor optical modulation circuit. In this way, a highly reliable optical flip-flop circuit is proposed which is operated at high speed by low voltage without causing deviation of an optical axis.
Further, JP-A-2-190019 discloses the following optical flip-flop circuit. The optical flip-flop circuit includes: a light receiving element; a light emitting element; a conductive passage for guiding an electric signal to the light emitting element; a light guiding passage for guiding an optical signal to the light receiving element; and an optical input and output portion which gives an optical input signal to the light receiving element and which guides an optical output signal outputted from the light emitting element, wherein all control signals and input and output signals can be processed by light.
However, structures of the optical flip-flop circuits, which have been conventionally proposed, are complicated and the costs of manufacturing the optical flip-flop circuits are necessarily raised. In the fields of optical communication and optical information, which will make rapid progress in future, it is desired to realize an optical flip-flop device, the structure of which is simple and the manufacturing cost of which is low.
The present invention has been accomplished in view of the above circumstances. It is an object of the present invention to provide an optical flip-flop circuit based on a new operation principle, the structure of which is simple and the manufacturing cost of which is low.